Preparation of cyanoalkylsilanes employing trihydrocarbyl arsine catalysts



United States Patent PLOYING TRIHYDRQCARBYL ARSINE CATA- Victor B. Jexand- John E. McMahon, Buifalo, N.Y.

No Drawing 'ApplicationJune 28,1957

1 Y Serial No. 668,622 r t 8 Claims. (Cl. 260-4482) This inventionrelates to a process for the production of new compositions of mattercomprising the beta-cyanoethylsilanes. More particularly, the inventionis concerned with a novel process for the production ofbetacyanoethylsilanes which contain at least one hydrolyzable groupbonded to the silicon atom thereof. This application is a continuationin part of application, Serial No. 555,201, filed December 23, 1955.

By reacting an alpha-beta olefinically unsaturated nitrile of the-typerepresented by acrylonitrile, methacrylonitrile, crotononitrile and thelike with a silane containing at least one hydrogen atom and at leastone hydrolyzable group bonded to the silicon atom thereof there isproduced a mixture of reaction products from which analpha-cyanoalkylsilane can berecovered. The overall reaction which takesplace can berepresented by the following equation, which depicts, forthe purpose of illustration, the reaction between acrylonitrile andtrichlorosilane. V

The present invention is based on our discovery that an alpha-betaolefinically unsaturated nitrile of the type represented byacrylonitrile, methacrylonitrile, crotononitrile and the like can becaused to react with a silane, containing at least one hydrogen atom andat least one Our process can be carried out by forming a mixture of theolefinic nitrile, a silane containing at least one hydrogen atom and atleast one hydrolyzable group bonded to the silicon atom thereof and asmall or catalytic amount of hydrocarbyl substituted arsines as catalystfor the reaction andheating 'the mixture to a temperature sufiicientlyelevatedto cause the starting mate rials to react. There results or isproduced a cyanoalkylsilane by the addition of a silyl group to theolefinic carbonatom of the nitrile further removed from the cyano groupand by the addition of a hydrogen atom to the .olefinic carbon atom ofthe nitrile closer to the cyano group. By the term hydrocarbyl, as usedherein, is means a monovalent organic group composed of carbon andhydrogen and includes saturated as well as unsaturated groups.

The silane starting materials containing at least one hydrogen atom andat least one hydrolyzable group bonded to the silicon atom thereof,which we employ in our process can be represented by the followinggeneral formula:

H-SiX -n wherein R represents a hydrogen atom or a hydrocarbyl group,preferably a saturated aliphatic or cycloaliphatic hydrocarbyl group asforexample, an alkyl group such as methyl, ethyl, propyl, butyl, pentyland the like and a cycloalkyl group such as cyclopentyl, cyclohexyl,methylcyclopentyl, ethylcyclohexyl, and the like or an aromatichydrocarbyl group, for example, an aryl group such as phenyl, naphthyl,tolyl, methylnaphthyl and the like, X is a hydrolyzable group such as ahalogen atom, preferably a chlorine atom, or a hydrocarbyloxy group,preferably an alkoxy or an aryloxy group such as methoxy, ethoxy,propoxy, phenoxy and the like, and n is a whole number having a value offrom 0 to 2. Illustrahydrolyzable group bonded to the silicon atomthereof,

in the presence of a catalyst to produce a beta-cyanoalkylsilane by theaddition ofa silyl group to the beta carbon atom of such nitrile, thatis the olefinic carbon atom further removed from the cyano group of thenitrile, and by the additionof a hydrogen atom to the alpha carbon atomof such nitrile, that is the vicinal olefinic carbon atom. Based' on ourdiscovery we have further found that any olefinic nitrile can be causedto react with a silane, containing at least one hydrogen atom and atleast one hydrolyzable group bonded to the silicon atom thereof, in thepresence of a catalyst to produce a cyanoalkylsilane by the addition ofa silyl group to the olefinic carbon atom further removed from the cyanogroup of the nitrile Coat ngs tive of the silane starting materials aretrichlorosilane, triethoxysilane, dichlorosilane, diethoxysilane,monochlorosilane, monoethoxysilane, methyldichlorosilane, ethyl-.diethoxysilane, diethylethoxysilane, dimethylchlorosilane,

butylethylchlorosilane, phenyldichlorosilane, phenylethylethoxysilane,dipropylphenoxysilane and the like.

The olefinic nitrile starting materials which we can employ in thepractice of our invention are the aliphatic mono-olefinic nitriles whichcontain from three to ten carbon atoms to the molecule. Illustrative ofsuch olefinic nitriles are acrylonitrile, methacrylonitrile, allylcyanide,

l-cyano-3-'butene, l-cyano-4-pentene, l-cyano-l-hexene and the like. Ourpreferred nitrile starting materials are the alpha-beta olefinicallyunsaturated nitriles, namely those nitriles in which the unsaturatedgrouping is directly bonded, through one of the carbon atoms thereof, tothe carbon atom of the cyano group. Such olefinic nitriles are commonlyknown as the vinyl-type cyanides and can be represented by the generalformula:

where R can b'e a hydrogen atom or an alkyl group as for example methyl,ethyl, propyl, butyl and the like and A is either a' hydrogen atom or amethyl group. Illus trative of such vinyl-type cyanides'areacrylonitrile, methacrylonitrile, crotononitrile and the like.

The hydrocarbyl substituted arsines which we employ as catalysts in ourprocess direct theaddition of the silyl group of our starting silane tothe .olefinic carbon atom of our starting nitrile further removed fromthe cyano group thereof and the addition of the hydrogen atom of thestarting silane to the vicinal olefinic carbon atom.

. v 3 Such catalysts are the trihydrocarbylarsines and can beillustrated by the formula:

RI! RI! wherein R" represents a hydrocarbyl group, as for .example analkyl or aryl group, which need not be necessarily the same throughoutthe arsine molecules. Illustrative of such alkyl groups are methyl,ethyl, propyi,

.isopropyl, butyl, isobutyl, 'pentyl, cetyl, eicosyl and the like; whileillustrative aryl'groups are phenyl, tolyl,-naphthyl and the like.Illustrative of such trihydrocarbyl substituted arsines are:trimethylarsine, triethylarsine, triphenylarsine, methyldiethylarsine,tri-n-butylarsine, and the like.

We have found that the amount of the catalyst employed in our process isnotnarrowly critical. Thus, amounts of the trihydrocarbylarsines of fromas little as about 0.2 part to as much as about parts by weight per 100parts of the total Weight of the starting materials can be favorablyemployed. We preferably employ the catalyst in an amount of from about0.3 part to about 3 parts by weight per 100 parts of the total weight ofthe nitrile and silane starting materials. Amounts of the trihydrocarbylsubstituted catalysts in smaller or greater quantities than thefavorable range can also be employed. However, no commensurate advantageis obtained thereby.

The olefinic nitrile and silane starting materials can be employed inour process in amounts which can vary from about one-half to 2 moles ofthe nitrile per mole of the silane. Preferably, the reactants areemployed in equimolar amounts. Amounts of either of the startingmaterials in excess of the ratios set forth above can also be employed;however, no commensurate advantage 'is ob tained thereby.

To facilitate observation and at the same time to favor closer controlof the reaction conditions, most ofour experimental work was carried outin pressure vessels or bombs, with agitation being provided if desiredby con tinuous shaking. Similar results can be obtained with flowingreactants in apparatus of known design permitting the maintenance of aclosed system. In the reactions with which our invention is concerned,itis desirable to maintain sufliciently high concentrations of thereactants (as measured for example'in moles per liter of reaction space)to promote effective contact between the molecules to be reacted. Whenone of the reactants is a gas, or a liquid readily volatile at thereaction temperature, and the reaction mixture is permitted to expandfreely on heating, the concentration of that reactant will fall to a lowvalue thus considerably slowing the reaction rate. If, however, thereactants are charged to a closed vessel which is sealed before heating,the initial concentration of any reactant falls off through itsconsumption by the reaction. If a. reactant is a gas, it may bedesirable to charge the reaction vessel to a considerable pressure tosecure an adequate concentration and reaction rate, and also to supplyenough of the reactant to produce an acceptable quantity of the product.

The temperatures which can be employed in carrying out our process arenot narrowly critical and can vary over a wide range. For example,temperatures as low as 40 C. and as high as 350 C. can be advantageouslyemployed. When conducting the process of the invention in a closedvessel a temperature in the range from about 75 "C. to about 250 C. ispreferred. Under such conditions, a reaction period of from about two toabout five hours is suitable. Temperatures of from about 175 C. to about300 C. are preferred whenconducting the process in apparatus whichprovides for the flow of the reactants and products while maintainingthe conditions of a closed system. In such systems, where the pressuremayrange from atmospheric upto 4000 pounds per square inch and 4 higher,the time required for the reaction to take place can be as short as0.005 minute.

In carrying out the process of our invention the product initiallyobtained comprises a mixture of compounds including the maincyanoalkylsilane as well as some unreacted nitrile and unreacted silanestarting compounds. The cyanoalkylsilane product, formed by the additionof a silyl group to the olefinic carbon atom of the nitrile furtherremoved from the cyano group and by the addition of a hydrogen atom tothe olefinic carbon atom closer to the cyano group, which contains atleast one hydrolyzable group bonded to thesilicon atom thereof, as forexample beta-cyanoethyltrichlorosilane, can be recovered therefrom bydistillation which is preferably conducted under reduced pressure.

The mechanism of our overall reaction wherein the silyl group isattached to the olefinic carbon atom of the starting nitrile furtherremoved from the cyano group and the hydrogen atom is attached to theolefinic carbon atom closer to the cyano group with the apparentsuppression of other addition or reaction products is not known withcertainty or fully understood. It isknown,

however, that upon heating our reactants in the absence of atrihydrocarbylarsine ascatalyst other reactions can take place such as:the formation of both siliconand non-silicon-containing 'free radicalsand complexes, the

homopolymerization of the starting nitrile, and even thedisproportionation of the starting silane has been observed. Inaddition, it is known that in the absence of our catalysts, ourpreferred starting materials can react to produce a mixture from whichan alpha-cyanoalkylsilane, wherein the silyl group is attached to the.olcfinic carbon closer to the cyano group and the hydrogen atom isattached to the other olefinic carbon more remote from cyano group, canbe recovered with no beta addition products being detected. One possibleexplanation for the course which our reaction follows when a silane andan olefinic nitrile react in the instance where the nitrile is avinyl-type cyanide is that the addition of the silyl group to theolefinic carbon atom more removed from the cyano group of the nitrileoccurs through an ionic mechanism while the addition of the silyl groupto the olefinic carbon atom closer to the cyano group of the nitrileoccurs through a free radical mechanism. If such is the case, then theactivation energy required for the reaction, between our startingnitriles and silanes, to proceed by a free radical mechanism isconsiderably less than that required to cause the reaction to proceed byan ionic mechanism. Consequently in the absence of our catalyst thereaction between an olefinic nitrile and a silane, as for exampleacrylonitrile and trichlorosilane will produce the alphaaddition productnamely, alphacyanoethyltrichlorosilane. On the other hand, ourtrihydrocarbylarsine catalysts apparently have the effect of markedlydecreasing the activation energy required for the reaction to proceed byan ionic mechanism and therefore when employed in such reactions, as forexample in the above acrylonitrile-trichlorosilane reaction, result inthe production of beta-cyanoethyltrichlorosilane.

,When the olefinic nitrile is of the type represented by allyl cyanide,that is, where the unsaturated grouping is removed by one'or more carbonatoms from the cyano group, our catalyst also functions in promoting thereaction thereof with our silane starting materials to produce additionproductsby the addition of a silyl group to the olefinic carbon atommore removed from the cyano group, and by the addition of a hydrogenatom to the olefinic carbon closer to the cyano group. By way ofillustration, gamma cyanopropyltrichlorosilane is prepared by reactingallyl cyanide with trichlorosilane in accordance with the subjectprocess.

Bis(cyanoalkyl)silanes are produced in the practice of the process ofour invention when our starting nitriles are reacted with silanescontaining at least two hydrogen atoms bonded to the silicon atomthereof. In such instances the nitrile starting material is preferablyemployed in an amount which is at least twice the number of moles of thestarting silane. Along with the desired bis compound, there is presentin the reaction mixture the cyanoalkyl hydrogensilane. By way ofillustration, ,when two moles of acrylonitrile are reacted with one moleof dichlorosilane in the presence of our trihydrocarbyl substitutedhydrides there is obtained, bis(beta-cyanoethyl)- dichlorosilane andbeta-cyanoethylhydrogendiohlorosilane. Alternatively, cyanoalkylhydrogen silanes can be used as starting materials for producingbis(cyanoalkyl)silanes. For example, thebeta-cyanoethylhydrogendichlorosil'ane is further reacted with anadditional amount of the starting nitrile to form bis(beta-cyanoethyl)dichlorosilane. In this manner the two cyanoalkyl groups are attached toeach silane molecule by two distinct reaction steps.

Still in accordance with our invention, the tris compounds can also beobtained by using as the starting material a silane containing at leastthree hydrogen atoms bonded to the silicon atom thereof. The triscompounds can be prepared by attaching the three cyanoalkyl groups toeach silane molecule in a single reaction step, in two successivereaction steps or in three successive reaction steps. Ourbeta-cyanoethylsilanes can be depicted eral formula:

by the genwhere R represents a hydrogen atom or hydrocarbyl group,preferably a saturated aliphatic hydrocarbyl group as for example, analkyl group, such as methyl, ethyl, propyl, butyl, pentyl and the like;a cycloalkyl group such as cyclopentyl, cyclohexyl, methylcyclopentyl,ethylcyclohexyl, and the like or an aryl group such as naphthyl, tolyl,methylnaphthyl and the like, X is a hydrolyzable group such as a halogenatom, preferably a chlorine atom or a hydrocarbyloxy group, preferablyan alkoxy or an aryloxy group such as methoxy, ethoxy, propoxy, phenoxyand the like, In is a whole number having a value of from 1 to 3 and nis a whole number having a value of from 0 to 2, with the sum of m and nbeing not greater than 3.

Illustrative of such new cyanoalkylsil-anes arebetacyanoethyltrichlorosilane, beta-cyanoethyltriethoxysilane, betacyanoethylmethyldichlorosilane, beta cyanoethyl methyldiethoxysilane,beta-cyanoethylethyldichlorosilane, beta-cyanoethylethyldipropoxysilane,beta-cyanoethylhydrogendichlorosilane,beta-cyanoethylhydrogendiethoxysilane,beta-cyanoethylphenyldichlorosilane,beta-cyanoethylphenyldipropoxysilane,beta-cyanoethyldirnethylchlorosilane,beta-cyanoethyldiphenylchlorosilane,beta-cyanoethylmethylhydrogenchlorosilane,beta-cyanoethylphenylhydrogenchlorosilane,beta-cyanoethyldiphenylethoxysilane,beta-cyanoethylmethylhydrogenethoxysilane,betacyanoethylphenylhydrogenethoxysilane, bis(beta cyanoethyl)diethoxysilane, bis(beta-cyanoethyl) diohlorosilane,bis(beta-cyanoethyl)methylethoxysilane,bis(betacyanoethyl)phenylchlorosilane,bis(beta-cyanoethyl)hydrogenohlorosilane,tris(beta-cyanoethyl)chlorosilane, tris(betacyanoethyl)ethoxysilane andthe like.

The beta-cyanoethylchlorosilanes of our invention can be employed as thestarting materials in the preparation of their correspondingbeta-cyanoethylhydrocarbyloxysilanes by reacting such materials with analcohol. By way of illustration, beta-cyanoethyltriethoxysilane isproduced by reaction of beta-cyanoethyltrichlorosilane with ethanol.Such is accomplished by the steps of forming a reactive mixture ofbeta-cyanoethyltrichlorosilane and ethanol, with or without a solventfor the silane.

Our beta-cyanoethylsilanes, by virtue of the hydrolyzable group orgroups bonded to the silicon atom thereof,

can be hydrolyzed to beta-cyanoethylpolysiloxanes. Hydrolysis of oursilanes is accomplished by the addition of such silanes to Water. Weprefer to carry out the hydrolysis reaction by first mixing thesubstituted silane with a liquid organic compound completely miscibletherewith, as for example, diethyl ether and adding such mixture to amedium comprising a mixture of water, ice and the organic ether. By wayof illustration, betacyanoethylpolysiloxane is produced by forming amixture of beta-cyanoethyltrichlorosilane with diethyl ether, as forexample, 100 parts of the silane and 20 parts of the ether and addingthe mixture to a beaker containing a mixture of water, ice and diethylether. There results a two-phase system, one of the phases being aqueoushydrochloric acid and the other phase being beta-cyanoethylpolysiloxanein diethyl ether. The aqueous hydrochloric acid phase is decanted andthe siloXane-solvent phase washed with water until the washings areneutral. Upon evaporation of the ether or other solvent from thenon-aqueous phase, preferably under reduced pressure there is obtainedas a residue a partially condensed beta-cyanoethylpolysiloxane. Thepartially condensed material can becompletely cured to a hard brittlepolymer. In a like manner, the difunctional beta-cyanoethylsilanes aswell as the monofunctional beta-cyanoethylsilanes can be hydrolyzed topolymeric compositions.

The difunctional beta-cyanoethylsilanes of our invention form cyclic aswell as linear polymers upon hydrol ysis. For example,beta-cyanoethylmethyldiethoxysilane upon hydrolysis produced in additionto a linear beta-,

temperatures as high as 200 C. The new linear and cyclic siloxanes finduse as oils in the lubrication of moving metal surfaces. The newmonofunctional silanes as well as their hydrolysis products, namely thecorresponding dimers, can be employed as endblocking compounds tocontrol the chain length of linear beta-cyanoalkylsilanes in theproduction of oils.

The following examples are illustrative of the present invention.

Example I To a 50 cc. steel pressure vessel were added 0.15 mole (20.3grams) of trichlorosilane, 0.15 mole (8 grams) of acrylonitrile and 0.56gram (2 percent by. weight) of triphenylarsine. The vessel was sealedand heated, while being rocked, to a temperature of 200 C. for a periodof two hours. After heating, the vessel was cooled to room temperature,the product removed therefrom and placed in a flask connected to adistillation column. The contents of the flask were heated to itsboiling temperature under reduced pressure and there was obtained 7.31grams of beta-cyanoethyltrichlorosilane boiling at a temperature of toC. under aredu'ced pressure of 5 to 7 mm. Hg.

In a similar manner trimethylarsine, triethylarsine, methyldiethylarsineand tri-n-butylarsine when respectively used in a similar process inplace of triphenylarsine can produce similar results.

Example 11 To a 500 ml. flask equipped with a condenser, a mechanicalstirrer, and dropping funnel was added a solution comprising 0.20 .mole(36.4 grams) of beta-cyanoethyltrichlorosilane dissolved in 75 ml. ofanyhdrous ethyl ether. While stirring the mixture, 0.58 mole (26.7grams) of ethanol was slowly added bymeans of the dropping funnel. Afterthe addition, the mixture was continually stirred for about three hoursafter which time it was heated to its boiling temperature under reducedpressure. There was obtained 24.2 grams ofbeta-cyanoethyltriethoxysilane boiling at 102 C. under a reducedpressure of 3.8 mm. Hg. Beta-cyanoethyltriethoxysilane has a density 11of 0.970 and a refractive index 11 of 1.4153. Elemental analyses forcarbon, hydrogen, silicon, nitrogen and ethoxy content were alsoconducted with the values obtained listed in the table below where theyare compared with the corresponding calculated values forbetacyanoethyltricthoxysilane:

Example 111 To a one liter flask equipped with stirrer and refluxcondenser were charged 100 cc. of a 3 percent water solution of sodiumhydroxide and 187 grams (1 mole) of betacyanoethylmethyldiethoxysilanedissolved in 400 cc; of diethyl ether. The mixture was stirred for'aperiod of about 4 hours after which time is was heated under reducedpressure to distill the ether and the ethyl alcohol formed during thehydrolysis reaction. The product was washed with water until neutral andthen dried over anhydrous sodium sulphate. The product was then added toa' flask and heated under reduced pressure to distill any residual etheror alcohol content therein. There was obtained 68 grams of a colorlessoil. The oil was then placed-in a flask connected to a Vigreux columnand heated to its boiling temperature. There wasdistilled 49 grams ofthe cyclic tetramer of beta-cyanoethylmethylsiloxane which wasidentified by elemental analysis as well as by infra-red analysis.Infra-red, analysis of the product remaining in the flask resulted inthe identification of the cyclic pentamer, hexamer and heptamer, of betacyanethylmethylsiloxane.

The cyclic tetramer of beta-cyanoethylmethylsiloxane has a'boilingtemperature of 277 to 280 C. under a re-.

duced pressure of 0.2 mm. Hg and a refractive index 11 of 1.4580. Thevalues appearing below were obtained from the elemental analysis of thecompound and are compared with the corresponding calculated values.

Cyclic Tetramer of Beta-cyancethylmethylsiloxane Found CalculatedCarbon, percent by weight 42. 6 42. 3 Hydrogen, percent by weight 6.06.14 Silicon, percent by weight. 23. 9 24. Nitrogen, percent by weight;12.1 12. 3 Molecular weight 474 r 456 Example IV [N OOHzOHzSiOS/i] wFound Calculated Carbon, percent by weight 29. 7 33. 9 Hydrogen, percentby weight. 3. 9 3.8 Silicon, percent by weight 25.0 26. 4 Nitrogen,percent by weight 12. 4 13. 2

Example V A sample of the beta-cyanoethylpolysiloxane prepared in theprevious example was placed in a weighing bottle and the bottle placedin a forced draft air oven maintained at a temperature of 250 C. for aperiod of 96 hours. The weighing bottle was then removed from the ovenand the polymer analyzed to determine the extent of decomposition causedby the elevated temperature. A variation in the elemental content of thepolymer before and after heating is an indication of the extent ofdecomposition. Inthe sample tested, the beta'cyanoethylpolysiloxane hada carbon content of 29.7 percent by weight before heating and a carboncontent of 26.3 percent by weight after heating. Such values indicatethat our beta-cyanoethylpolysiloxane retains 88.3 percent of its carboncontent at elevated temperatures, which makes the polymers desirable asa protective coating.

What is claimed is:

1. A process for reacting a silane, represented by the formula:

, where R represents a member of the group consisting of hydrogen and ahydrocarbyl group, X represents a hydrolyzable group from the classconsisting of halogen and hydrocarbyloxy group and n represents a wholenumber having a value of from 0 to 2, with a mono-olefinic aliphaticnitrile having from 3 to 10 carbon atoms and containing the unsaturatedolefinic grouping cats to produce a cyanoalkylsilane by the addition ofa silyl group to the carbon atom of said unsaturated grouping furtherremoved from the cyano group of said nitrile and by the addition of ahydrogen atom to the carbon atom of said unsaturated grouping closer tothe cyano group of said nitrile, which comprises forming a mixture ofsaid silane, said nitrile and a trihydrocarbylarsine heating saidmixture to a temperature sufliciently elevated to cause said silane andnitrile'to react to produce a cyanoalkylsilane by the addition of asilyl group to the carbon atom of the unsaturated grouping furtherremoved from the cyano group of the starting nitrile and by the additionof a hydrogen atom to the carbon atom of the unsaturated grouping closerto the cyano group of the starting nitrile and recovering thecyanoalkylsilane.

where R represents a member of the group consisting of hydrogen and ahydrocarbyl group, X represents a hydrolyzable group from the; classconsisting of a halogen atom and' a hydrocarbyloxy group, and nrepresents a whole number having a value of from 0 to 2, with a nitrilehaving from 3 to 10 carbon atoms and the formula:

olefinic carbon atom of the nitrile further removed from the cyano groupthereof and by the addition of a hydrogen atom to the olefinic carbonatom of the nitrile closer to the cyano group thereof which comprisesforming a mixture of said silane, nitrile, and a trihydrocarbylarsine,heating said mixture to a temperature sufliciently elevated to causesaid silane and nitrile to react to produce a cyanoalkylsilane byaddition of a silyl group to the olefinic carbon atom further removedfrom the cyano group of the starting nitrile and by the addition of ahydrogen atom tothe olefinic carbon atom closer to the cyano group ofthe starting nitrile.

which comprises forming a mixture of a silane of the formula:

' H-Sl-Xu-m where R represents a member of the group consisting ofhydrogen and a hydrocarbyl group, X represents a hydrolyzable grouptaken from the class consisting of a 3. A process for producing abeta-cyanoethylsilane which comprises forming a mixture of a silane ofthe formula:

(n) (I-a) where R represents a member of the group consisting ofhydrogen and a hydrocarbyl group, X represents a hydrolyzable group fromthe class consisting of a halogen atom and a hydrocarbyloxy group and nrepresents a whole number having a value of from 0 to 2, acry1onitrileand a trialkylarsine catalyst, heating said mixture to a temperaturesufliciently elevated to cause said silane and acrylonitrile to react toproduce a beta-cyanoethylsilane.

4. A process for producing a beta-cyanoethylsilane which comprisesforming a mixture of a silane of the formula:

0") where R represents a member of the group consisting of hydrogen anda hydrocarbyl group, X represents a hydrolyzable group taken from theclass consisting of a halogen atom and a hydrocarbyloxy group and nrepresents a whole number having a value of from 0 to 2, acrylonitrileand a triarylarsine catalyst, heating said mixture to a temperaturesufiiciently elevated to cause said silane and acrylonitrile to react toproduce a betacyanoethylsilane. l

5. A process for producing gamma-cyanopropylsilane halogen atom and ahydrocarbyloxy group and n repre sents a whole number having a value offrom 0 to 2, allyl cyanide and triarylarsine, heating said mixture to atemperature sufliciently elevated to cause said silane and alllylcyanide to react to produce a g'amma-cyanopropyls1 ane.

6. A process for producing gamma-cyanopropylsilane which comprisesforming a mixture of a silane of the formula:

drolyzable group taken from the class consisting of a halogen atom and ahydrocarbyloxy group'and n represents a whole number having a value'offrom 0 to 2, allyl cyanide and trialkylarsine, heating said mixture to atemperature sufliciently elevated to cause said silane and allyl cyanideto react to produce a gamma-cyanopropylsilane.

7. -A process for producing beta-cyanoethyltrichlorosilane whichcomprises forming a mixture of acrylonitrile, trichlorosilane andtriphenylarsine, heating said mixture to a temperature suificientlyelevated to cause said acrylonitrile and trichlorosilane to react toproduce betacyanoethyltrichlorosilane.

8. A process for producing beta-cyanoethyltrichlorosilane whichcomprises forming a mixture of trichlorosilane, acrylonitrile and about0.2 to 10 weight percent of triphenylarsine based on the mixture weight,heating said mixture to a temperature sufiiciently elevated to cause theacrylonitrile and trichlorosilane to reactto producebetacyanoethyltrichlorosilane.

References Cited in the file of this patent UNITED STATES PATENTS2,524,529 Krieble Oct. 3, 1950 2,532,583 Tyran Dec. 5, 1950 2,632,013Wagner et al Mar. 17, 1953 2,675,372 Coover et a1 Apr. 13, 19542,716,638 Cohen et a1 Aug. 30, 1955 2,721,873 MacKenzie et a1 Oct. 25,1955 2,823,218 Speier et a1. Feb. 11, 1958 UNITED STATES PATENT OFFICEICERTIFIQATE I CORRECTION Patent No., 2311,4236 November S 1959 7 VictorBa Jex et a1,

It is hereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below,

In the grant lines 1, 2 and 3, for "Victor BB Jex and John E. McMahon ofBuffalo, New York 'f read Victor Be Jex and John E, McMahon, of Buffalo,New York assignors to Union Carbide Corporation, a corporation of NewYork, line 12, for "Victor B Jex and John E McMahon, their heirs" readUnion Carbide Corporation, its successors in the heading to the printedspecification line 5 for "Victor 13.. Jex and John E. McMahon, BuffaloN, Y, read Victor Be Jex and John E. McMahon Buffalo N.a Ye assignor toUnion Carbide Corporation a corporation of New York Signed and sealedthis 27th day of December 1960a (SEAL) Attest:

KARL H. AXLINE ROBERT Co WATSON Attesting Officer Commissioner ofPatents

1. A PROCESS FOR REACTING A SILANE, REPRESENTED BY THE FORMULA: